Ascertainment and consideration of likely
environmental impacts is an essential part of project planning1).
The necessary scope of a study on environmental impacts and
environmentally sound project design will depend on the extent of
the anticipated environmental stresses, the sensitivity of the
environmental components requiring protection, the complexity of
the project, the availability of information and the stage of
appraisal. Particular attention must be focused on projects which
typically involve major environmental risks, such as industrial
plants producing significant emissions (e.g. refineries),
infrastructure measures whose potential impacts are difficult to
assess (e.g. construction of new cross-country roads/effects
resulting from accessibility) and projects involving extensive
interference with the balance of nature (e.g. mining, wood
production, utilisation of water etc.). A detailed study will
generally be required in such cases.

1) The purpose of the study is to
provide a basis for project planning and appraisal. The results
may be presented in the form of a separate study or as part of a
feasibility study.

The following key environmental aspects must
also be considered for other environmentally relevant projects:

- actual ecological situation in the
project region or with respect to specific ecosystem
- existing stresses on the various ecosystems in the planned
project location and their likely development if the project
is not implemented (baseline state)
- description of the additional stresses imposed by the
project and its alternatives
- estimation of future overall stresses
- interaction between ecological, economic, cultural and
social effects
- impacts on women to be considered separately
- recommendations for environmentally sound options
(alternative methods, emission-limiting requirements),
including determination of suitable location
- overall evaluation

In order to lay down the framework and likely focal
areas of an environmental study, the nature, reach and
significance of the planned project's potential environmental
impacts must be estimated with the aid of the usual documentation
and relevant materials. The basis is provided by information
about the project's design and context, the occurrence, dispersal
and eventual whereabouts of pollutants, direct and indirect
physical interference with ecosystems that affects natural
cycling systems, and primary and anticipated secondary impacts on
the socio-economic situation of the project region's population.
Appropriate terms of reference for the study must then be
elaborated on the basis of this information.

B. Basis for investigating environmental
impacts

1. Initial information can be derived from the
project documents. It must be ensured that these documents
provide concrete details that can be drawn upon in assessing
environmental aspects. This applies in particular to areas of
significance both in technical and economic terms as well as from
the ecological viewpoint. Foremost among these are the following:

Where necessary, more detailed information is
to be collected during elaboration of a feasibility study, making
use of local knowledge where appropriate.

2. In order to determine who is to compile the
study and with whose assistance, it is necessary to ascertain the
existing scientific and technical expertise, the regulations
applied and the extent to which statutory requirements and
relevant findings are put into practice. If the structures for
ensuring compliance with environmental requirements are
considered effective, for example, the environmental study may be
confined to particularly difficult and atypical problems.

C. Content and structure of the
environmental study

The structure set out below is intended to help
ensure that account is taken of all significant environmental
impacts in the project region as well as upstream and downstream
sectors. Experience has shown that serious environmental damage
occurs in cases where follow-on problems were not spotted in
advance; one way of preventing such a development is to lay down
comprehensive terms of reference. The structure given should be
regarded as the maximum scope for a study and is to be used in
its complete form whenever complex environmental impacts (as
described in A above) are anticipated.